Multidimensional Dynamics of Type II Supernovae

流体动力学（HD）的研究在以下几个领域至关重要： 天体物理学 其中一个领域涉及某些简短的阶段 恒星演化的过程，持续数分钟甚至数秒， 星星的结构变化非常迅速， 影响他们的进化。 这些事件中最常见的 大质量星星的核心突然坍缩，导致爆炸 超新星（SN） 人们早就知道， 超新星爆炸形成的“壳”聚集成碎片， “象鼻”结构表明HD不稳定性， 超新星爆炸波扩散到星际空间。 最近的 超新星SN 1987a在大麦哲伦星系的观测 云显示“指”形结构富含元素镍 在爆炸后几周甚至几天内发展起来的 的 主要研究者（PI）计划使用新的HD数值 计算程序，分段抛物方法（PPM）， 进行爆震和爆炸的数值模拟， II型超新星，如SN 1987a。 新技术一般 远比旧的更有效，并将允许计算， 在两个甚至三个维度上进行，从而允许 了解这些小结构的发展 残余物。 此外，与合作研究者和学生，PI 将利用新的对流理论， 理解所观察到的气体“斑点”的漩涡。 许多沉重的 地球上的元素在关键时刻合成 在这次爆炸之后。 现在看来重元素 由于镍在小“指”中不均匀地合成， 结构. 这个项目应该提供一些了解如何 以及为什么会出现这种重元素的不均匀形成。 的 为这项研究开发的技术和计算机程序是 预计将在未来的几个其他天体物理应用中找到应用 背景下，如I型超新星（在热白色 双星星星伴星的矮星），大幅度脉动 变星和稳定恒星中的对流，比如太阳。

The study of hydrodynamics (HD) is critical in several areas of astrophysics. One of those areas concerns certain brief phases of stellar evolution, lasting minutes or even seconds, in which very rapid structural changes can occur in the star, critically affecting their evolution. The most common of these events in the sudden core-collapse of a massive star, leading to the explosion of a "supernova" (SN). It has long been known that the remnant "shell" from supernova explosions aggregates into filamentary and "elephant trunk" structures that indicate HD instabilities as the SN blast wave expands into interstellar space. The most recent observations of the supernova "SN1987a" in the Large Magellanic Cloud show "finger" shaped structures rich in the element nickel that developed weeks or even days after the explosion. The Principal Investigator (PI) plans to use a new HD numerical calculation procedure, the Piecewise Parabolic Method (PPM) to perform numerical simulations of the detonation and explosion of Type II supernovae such as SN1987a. The new technique is generally far more efficient than old ones and will permit calculations to be done in two and even three dimensions, thereby permitting an understanding of the development of small structures in these remnants. Moreover, with a Co-Investigator and student, the PI will utilize a new theory of convection that is essential to understand the observed swirling of gas "blobs". Many of the heavy elements on the Earth are synthesized during the critical moments following this explosion. It now seems that heavy elements such as nickel are synthesized unevenly in the small "finger" structures. This project should provide some understanding of how and why this uneven formation of heavy elements occurs. The techniques and computer programs developed for this study are expected to find future application in several other astrophysical contexts, such as Type I supernovae (accreted matter on a hot white dwarf from a double star companion), pulsation in large amplitude variable stars, and convection in stable stars such as the Sun.